Journal of Plant Pathology (2010), 92 (4, Supplement ... - Sipav.org

Journal of Plant Pathology (2010), 92 (4, Supplement), S4.71-S4.105 S4.79
ANTIFUNGAL ACTIVITY OF ALCOHOLIC EXTRACT
FROM SPARTIUM JUNCEUM : PRELIMINARY SCREEN-
ING STUDIES. F. Clematis, C. Pasini, P. Curir. CRA, Unità di
Ricerca per la Floricoltura e le Specie Ornamentali (CRA-FSO),
Corso Inglesi 08, 18038 Sanremo (IM), Italy. E-mail: f.clematis@
istflori.it
The antifungal properties of Spartium junceum, a perennial
shrubs native to the Mediterranean area and widespread throughout
Italy, were tested against eight selected fungal pathogens.
Plant material (stem and leaves) were extracted with ethanol (1:1)
in a soxhlet apparatus under refluxing conditions for 3 h. The efficacy
of plant extracts was tested in vitro by poisoned food technique
at different concentrations (2, 1.6, and 1%). The best inhibition
values ranged between 21.3 and 46%. The highest concentration
of plant extract (2%) showed significant reduction on the
growth of Fusarium oxysporum isolated from Danae racemosa and
F. oxysporum f. sp. dianthi, while the lowest concentration (1%)
was already effective in suppressing Alternaria dianthi and Botrytis
cinerea. A. dianthi was inhibited by 46.0% when 2% of plant
extract was applied, B. cinerea and both F. oxysporum strains
were inhibited by 45.3 and 37.3%, respectively. This preliminary
screening showed significant inhibition activity of S. junceum extracts
already at low concentrations. Preliminary TLC and spectrophotometer
analysis showed the presence of phenolic compounds
in the extracts using UV absorbance at 275 nm. Investigations
are in progress to study the phytochemical characteristics
of plant extract by HPLC and TLC.
AN APPROACH TO GRAPEVINE SANITARY SELEC-
TION IN SARDINIA: FIELD STUDY AND SEROLOGICAL
DIAGNOSIS. L. Cogotzi, V.A. Prota, R. Garau. Dipartimento di
Protezione delle Piante, Sezione di Patologia Vegetale, Università
degli Studi, Via Enrico De Nicola 1, 07100 Sassari, Italy. E-mail:
lcogotzi@uniss.it
Strategies to control viruses are essentially preventive and
based on sanitary selection programs. Within this project, the creation
of a germplasm collection will aim at progressive sanitary
selection. Field studies, carried out over two years (2008-2009),
focused on eleven local grapevine varieties: Vermentino, Cannonau,
Monica, Bovale, Malvasia, Carignano, Nuragus, Nebbiolo,
Moscato, Caricajola, and Nasco. Selected vineyards were inspected
in spring, summer and autumn. Symptoms of virus and
phytoplasma infections were common in these vineyards. Almost
5000 essentially symptomless vines were selected in the course of
numerous field surveys carried out throughout the entire region
and were tested serologically (ELISA). We focused on the presence
of two types of viruses associated with leafroll disease
(GLRaV-2, GLRaV-3) that cause severe losses, reduce yield and
impact negatively fruit quality. Grapevine fanleaf virus (GFLV)
and Grapevine virus A (GVA), an agent associated with Kober
stem grooving were also looked for on a lower number of plants.
Results showed that, in Sardinia, infection rates of GLRaV-2,
GLRaV-3, GFLV and GVA range between 3 and 70%, 5 and
80%, 0 and 40% and 5 and 60%, respectively. ‘Carignano’ from
the Sulcis area (south-west Sardinia) had the highest percentage
of virus-free plants while ‘Nuragus’ and ‘Malvasia, both from the
south of Sardinia (Parteolla area) had the lowest. Selected plants
will undergo further sanitary selection.
Work funded by the Con.Vi.Sar. consortium of Sardinia
PLANT VIRUSES AS POSSIBLE PLATFORMS FOR MOLE-
CULAR FARMING. V. Condelli, A. Vitti, M. Nuzzaci, M.T.
Lanorte, P. Piazzolla. Dipartimento di Biologia Difesa e Biotecnologie
Agro-Forestali, Università degli Studi della Basilicata, Campus
di Macchia Romana, Via dell’Ateneo Lucano 10, 85100 Potenza,
Italy. E-mail: valentina.condelli@unibas.it
Plant viruses are emerging as an attractive system for the expression
of foreign epitopes used as immunogens for the development
of innovative vaccination strategies. In such a way, plant
viruses carrying on their coat protein (CP) peptides of medical
interest can be considered, in association with their hosts, right
partners of biological systems devoted to pursue the goal of functioning
as medical molecular farming. Cucumber mosaic virus
(CMV) is one of the plant viruses used as a carrier of foreign epitopes
because of its wide host range, which comprises edible
plants (celery, lettuce, cucumber, tomato, carrot, pepper, banana,
ecc). The results of immunological experiments, obtained by using
CMV as a presentation system for the Hepatitis C virus- and
Alzheimer’s disease-derived epitopes, in association with the
proven stability of CMV in gastrointestinal environment, seem to
open a new prospect for the development of effective vaccine
candidates. These data could be considered of paramount importance
to health and medicine, thus suggesting to extend this strategy
to other human and animal diseases, such as Influenza. Alternatively,
another plant virus, Potato virus A (PVA) was selected as
a carrier because the filamentous shape of its particles offers no
packaging limitation for rather large genome insertion. A molecular
modeling approach has been used to identify the possible insertion
points of foreign determinants, in order to get the best
conditions of stability and infectivity of chimeric virus particles.
MYCOTOXIGENIC FUSARIUM SPECIES AND MYCO-
TOXINS IN WHEAT GRAIN IN 2008 IN UMBRIA. L. Covarelli,
G. Beccari, M. Tinelli, G. Santoponte. Dipartimento di
Scienze Agrarie e Ambientali, Università degli Studi, Borgo XX
Giugno 74, 06121 Perugia, Italy. E-mail: lorenzo.covarelli@
unipg.it
In 2008, a study was conducted on 53 durum wheat (DW)
and 36 soft wheat (SW) grain samples harvested in Umbria (central
Italy). After visual observation of Fusarium damaged kernels,
samples were subjected to fungal isolation on PDA, DNA extraction
for Fusarium detection and identification by PCR, mycotoxin
extraction for deoxynivalenol (DON) and T-2 toxin determination..
DW and SW samples had 34% and 19% Fusarium-damaged
kernels while average the incidence of Fusarium infections
was 40% and 33%, respectively, in the two wheat species. PCR
assays showed that the most frequent species were F. graminearum,
F. avenaceum and F. culmorum. F. equiseti was also detected
by PCR but was not isolated on PDA while F. poae was mainly
detected by traditional isolation rather than by PCR. DON levels
exceeded the EU legal limits in 9% of DW and 8% of SW samples,
reaching contamination levels of 53 mg kg -1 in DW (average
2 mg kg -1 ) and 10 mg kg -1 in SW (average 0.7 mg kg -1 ). T-2 toxin
was constantly detected, with peaks of 187 µg kg -1 in DW (average
62 µg kg -1 ) and 78 µg kg -1 in SW (average 40 µg kg -1 ). Our results
indicate that, even if previous studies carried out in Umbria
showed a low mycotoxins risk, in years like 2008 that was characterized
by climatic conditions extremely favourable to Fusarium
head blight, wheat contamination may represent an important
problem also in the examined area.